Driving mechanism.



l H. WILLIAMS.

DRIVING'MECHANISM.

' APPLICATION FILED Amso. 1912.

'Patented Nov. 30, 1915.

HARRY WILLIAMS, OF GLASGOW, SCOTLAND.

DRIVING MECHANISM.

i y Speccation of Letters Patent. l Patnted NOV, 3Q, 19111 Appncatin filed April 30,1912. serial No. 694,189.

T0 all wLom t may concern Be it known that I, HARRY WILLIAMS, subject of the King of Great Britain, residing at Glasgow, Scotland, have invented certain new and useful Improvements in Driving Mechanism, lof which the following is a specification.

This invention relates to improved driv ing gear for use in steamgas oil and like engines or for pumps and like driven appliances.

The object of the present invention is to which is arranged about or adjacent to the.

path of the sliding member and is composed of the combination of a considerable oscillating movement about a pin on the sliding member, conveniently about 1800, and the reciprocating movement of the sliding member. For this purpose I propose to employ revolving crank pins at a fixed angular relation, two connecting rods and an oscillating lever or its equivalent on the slider. The essential of the present invention, is that the connecting rods at an early stage in and duringthe motion tend to successively come into a tangential position with respect to the crank and for this purpose the oscillating lever must have its arms of a radius less than the crank and` preferably about one-half the crank radius, which is a novel relation productive of the effect stated. The cranks moreover should not be more than about 90o apart. In other words, the distance between the outside centers of the oscillating link should be equal to or only very slightly greater than the chord joining the, centers of the two crank pins. With this construction, the oscillating lever swings through an angle of about 1800, and the centers of the levers follow a path like a horizontal 8, with the two loops of the 8 very nearly touching the straight line path -should also be stated that the radius of revolution of the crank pins is greater than half the piston or slider stroke.

In practice, I have found after a series of rigorous tests that a considerable increase in the brake horsepower with the same steam consumption'may be obtained by substitut ing my novel driving gear for the ordinary gear. A pumping test has shown that the fluid friction losses with this improved gear are materially reduced owing -to the peculiar relation of the piston speed to theport or valve opening throughout the stroke. The engine runs more steadily and the maximum stress on the working parts is also reduced by a material amountowing to the greater uniformity of the effort.

`The invention may further be said concisely to consist in a driving gearfor an engine pump or vthe like comprising two cranks, of a radius greater than half the piston stroke, connected by'two connecting rods to the opposite ends of a lever pivoted at its center' on the crosshead or sliding member and having its arms of a lesser radius than the crank, whereby the oscillating lever swings through ank angle of about ISOOduring each revolution of `the crank. The cranks should not be` more and are prefer ably' less than about 90 apart and the centers of the pins von the oscillating link are approximately the same distance apart as they chord joining theA crank pin centers. The connecting rods are preferably arranged to cross at the inner dead center of thecranks, that is when the crank pins are vec nearest to the path of reciprocati'on of the slider or reciprocating member.

Referring now to the accompanying drawings which illustrate this invention in one form, Figure 1, is a side elevation of one form of the mechanism vwhich I may employ'. Fig. 2, is a plan. Fig. 3, is an end elevation looking `on the cranks and Fig. 4,

is a diagrammatic representation of the essential parts of the gear shown 1n Fig. l.

Fig.i5, is a side view and Fig. 6, is a plan of a modied construction.

In carrying out the invention according to the particular form illustrated in the drawings as applied to an engine. the crosshead sliders a, have freely mounted within them pins Z), on which two oscillating disks c, CZ, are fixed. VThe pins b, are also embraced by the forked end e, of the piston rod f, which is continued rearwardly and connects to the piston f, in an ordinary manner. The piston f', reciprocates in the cylinder 4The pins Z), are continued laterally through the disks c, and (Z, and are suitably riveted or otherwise fixed therein. rIhe disks c and cZ, are further connected by pins g and 7i, arranged diametrically opposite one another.

It is evident that the two disks may each be narrowed so that they become mere links or levers, just as a common crank plate may be changed to a simple crank, and in Fig. 4

nected, oppositely extending cranks.

The pins g and h, are connected by connecting rods 71 and j, respectively to crank pins and Z. The 'crank pin Z, is fixed on a crank disk m, andthe crank pin lo, is fixed on a crank disk n. The two crank pins 7c and `Z, are connected by a link 0. The connecting rods Z and jare conveniently offset as shown. The rods and j, may be arranged to cross at the outer dead center,but it is preferable to arrange them open at the outer dead center as shown in Fig. 1, as by this arrangement the advantages of this invention are obtained in a greater degree.`

The centers of the pins g and t, are also preferably slightly farther apart' than the centersy ofthepins 7c and Z, but the centers of the pins g and h, should always be nearer together than ytwice the crank radius.

The advantages of this invention are however, obtained in a very much decreasing degreel if the cranks exceed 90O apart and if the centers on the oscillatinglink are farther apart than Ita/2, where R is the crank radius. an angle rather less than 90o, for the cranks and the centers of the oscillating link correspondingly reduced.

It will be seen fromv the above that owing to the opening and crossing of the connecting rods i and y', I am able to shorten the piston travel considerably, while maintaing the same crank path. The amount of the variation in the length of the intermediate gear or linkage between the piston f, and the crank pin is exemplified by the relative lengths L and L in Fig. 1, which shows the lengths at the two end positions of the piston. This results in' a still greater increase in leverage with a shorter piston stroke than would be obtained by'using open rods atthe inner dead center. It will be seen that by The best results are obtained withv means of this invention I reduce the volume of displacement in the cylinder at each end of the stroke and the total amount of this reduction is equal to the difference between the diameter of the crank pin circle and the piston travel.

The advantages of increasing the diameter -g and 7L each travel in adouble looped path resembling a horizontal 8, with its two loops lying approximately but not quite on the plane of motion of the crosshead as shown at Z by dotted lines in Fig. 4. The crosshead ends G and H, of the connecting rods are thus caused 4to recede or double back at opposite ends of the piston stroke. Thus on reference to Fig. 4, it will be seen that the pin G, recedes when the link travels from right to left. At the opposite end of the stroke, the pin G, will recede or double back when the piston starts its motion from left to right. If the rotation were reversed the pin I-I,.would recede and double back. It should also be pointed out that by virtue of the curved path of the pins g and 71 the rods z' and j, successively tend to assume the nearest possible position to thetangential and thereby the piston pressure is transmitted in the case .of engines in the most favorable fashion to the crank shaft. About the center of the piston stroke, the two rods are both approximately parallel.

On plottingA out the piston velocities with a uniform angular velocity of Athe crank, it is found that the initial piston velocity is considerably lessv with this form of driving gear, than with the ordinary form of connecting rod. This reduction in the initial piston velocity gives more time for the steam to enter the cylinder in steam engines and is also of materialusefin reducing valve losses 1n pumps.

5 and 6, this disk 6, is reduced at its centralk part 7, where it finds a bearing in the cross head 8. Suitableslippers 9, are fixed in any convenient manner to the crosshead 8. The pins 16, 17, on the oscillating disk 6, arearranged on opposite sides and the connecting rods 10 are connect-ed, so as to cross at the inner dead center, to two crank pins 11 and 12. In this form also one of the crank webs is dispensed with and what is known as an overhung crank construction is employed. In this construction, I prefer `to make the crank 13, pins 11 and 12, and web 1&1, all in one piece of metal. The driving force from the pin 12, is transmitted through the web 1i, pin 11 and crank 13, to the rotating shaft 15. The reduced part 7, of the disk 6, is left of sufficient diameter to provide ample bear-- ing surface for the crosshead pin. The oscillating pins 16 and 17, need not be so large. The crank pin 11, should be larger and stronger than the pin 12.

' It will be readily appreciated by those engaged in this art that the balancing of an engine such as herein described may be carried out very fully and perfectly owing in the first place to the tangential manner in which the force is transmitted to the crank pins and owing to the fact that the crossheads so far as they may not be balanced by weighting the crank may be perfectly balanced by suitably weighting the oscillating disk. In this connection it may be stated however that the two connecting rods appear to balance one another to a marked degree. From comparativetests made on a small engine with a very late cut off and irst with my improved slider crank gear and then with an ordinary connecting rod, it would appear that approximately the same power lis obtained from the two engines working with the same crank pin circle and under similar conditions. This would mean that with the improved gear the same power is obtained with a much smaller stroke of piston and consequently with much less steam.

The following is submitted as another probable method of regarding the improved crank gear. The displacement of the piston (in the case of an engine) before the connecting rods of my improved gear start to transmit a substantially tangential force, is less than in the case of the ordinary slider crank gear and the difference in displacement between the pistons in the two gears probably gives some approximation to the reduction in steam consumption.

I claim 1. A driving gear comprising a sliding member movable in a straight line path, a rotating member having two cranks in ixed angular relation, an oscillating member on the sliding member, and connecting rods connecting the cranks with diametrically opposite points on the oscillating member, thel distance between. said points and the axis of the oscillating member being substantially 4less than the radius of the cranks,

whereby the oscillating member swings through an arc of approximately 180, its line of centers being brought alternately approximately in parallelism with the lineo movement ofthe slidingmember. y

2. A driving gear comprising a slider, a crank shaft having cranks set at less than 900, an oscillating member on the slider ment of the slider diering from each other by more than the minimum distance of said path from said line.

3. In reciprocating engines, and pumps a reciprocating member, a rotating member and transmission and converting mechanism between said members comprising two crank pins maintained at an angle apart less than 90, and moving in a circle of greater diameter than the stroke of the reciprocating member, an oscillating member mounted centrally to move with but oscillate on said reciprocating member, pins carried by said oscillating member at diametrically opposite parts with respect to the center of oscillation, said pins being at distances from the center of oscillation approximately half the radial distance of the crank pins from their center of oscillation, and connecting rods from said pins on the oscillating member to the said crank pins.

4. In reciprocating engines, and pumps a reciprocating member, a rotating member and transmission and converting mechanism between said members, comprising two crank pins maintained at an angle apart less than 90O and moving in a circle of greater position of said cranks when said crank pins are nearest to the pathv of reciprocation of said reciprocating member.

5. In engines and pumps, a rotating member, a reciprocating member, two oscillating plates mounted to move with but oscillate on said member, cross connecting pins bemetrically opposite to oscillate back and folward with said plates through an angle of substantially 180", two cranks maintained at a Constant angle less than 90 apart, pins on said cranks, the distance of the pins carried by the oscillating plates from the axis of the oscillating plates being substantiallyy less than the radius of the cranks, and twoy connecting rods from said crank pins t0 said 10 pins on the oscillating plates.

, In testimony whereof I have signed my naine to this specification in the presence of two subscribing witnesses.

HARRY WILLIAMS.

Witnesses:

JAMES MATHER, Jr., GERTRUDE H. MACREADIE.

Copies of this patent may 'be obtained for five cents each, by addressing the Commissioner of Patent?.`

Washington, D. C. 

